Question

1. in a nuclear reaction, which quantity is the same before and after the change? (mass number. what is it composed of?) 2. how does an alpha - particle emission change an atom? 3. when modeling radioactive decay you must ensure that an unstable able to become a stable 4. what is the difference between fusion and a chemical reaction? 5. describe what happens during a nuclear fusion reaction. 6. name the following type of reactions as fusion or fission a. large nucleus → multiple smaller nuclei + neutrons b. multiple small nuclei → large nucleus + energy c. the number of nucleons stays the same, number of nuclei increases

Explanation:

Step1: Answer question 1

In a nuclear reaction, the quantity that is the same before and after the change is the total number of nucleons (protons + neutrons). This is due to the law of conservation of nucleon - number in nuclear reactions.

Step2: Answer question 2

An alpha particle has 2 protons and 2 neutrons. When an alpha - particle is emitted, the mass number of the atom decreases by 4 (since an alpha particle has a mass number of 4) and the atomic number decreases by 2 (as it has 2 protons).

Step3: Answer question 3

When modeling radioactive decay to ensure an unstable nucleus becomes stable, we must conserve mass - number and atomic number. The decay products must account for the change in the parent nucleus's mass - number and atomic number such that the total mass - number and atomic number before and after decay are equal.

Step4: Answer question 4

The difference between a fusion and a chemical reaction: In a fusion reaction, atomic nuclei combine to form a heavier nucleus, and it occurs in the nucleus. It involves a change in the identity of the elements at the nuclear level. In a chemical reaction, atoms are rearranged through the breaking and forming of chemical bonds, and the nuclei remain unchanged.

Step5: Answer question 5

The process described is fission. In fission, a large nucleus splits into multiple smaller nuclei and neutrons, releasing energy.

Step6: Answer question 6

The process described is fusion. In fusion, multiple small nuclei combine to form a large nucleus and release energy.

Answer:

1. Total number of nucleons
2. Mass number decreases by 4, atomic number decreases by 2
3. Conserve mass - number and atomic number
4. Fusion involves nuclear change of elements, chemical reaction involves atomic - level bond rearrangement
5. Fission
6. Fusion